Safety device for paper-cutting machines



c. F. PFLANZE.

SAFETY DEVICE FOR PAPER CUTTING MACHINES.

APPLICATION FILED TANJG. I917.

1,332,856. T Patented Mar. 2,1920;

2 SHEETSSHEET 1- C. F. PFLANZE.

SAFETY DEVICE FOR PAPER CUTTING MACHINES.

- APPLICATION FILED JAN. 16. um.

1,332,856; Patented Mar. 2,1920.

2 SHEETS SHEET 2.

UNITED STATES PATENT OFFICE.

CHARLES F. PFI IANZE, OF ST. LOUIS, MISSOURI.

SAFETY DEVICE FOR PAPER-CUTTING- MACHINES.

Specification of Letters Patent.

Patented Mar. 2, 1920.

Application filed January 16, 1917. Serial No. 142,598.

- tion;

'formance of their functions.

My invention relates to a safety device adapted to stop the knife orpressure bar of a paper cutting machine, but it is to be understood"that the invention is not limited to such use. It may be used as a stopfor the driven members of various different kinds of machines.

Prior to this invention, paper cutting machines have been provided withautomatic stopping devices including an automatic clutch shifter forreleasing the driven mechanism from the source of power, and anautomatic brake for stopping the driven. mechanismythe object being tostop the reciprocatory cutting elements in an elevated position aftereach cutting operation. The cutting elements usually include a large,heavy knife carrier and a heavy clamping bar or pressure bar whichreciprocate in re sponse to the rotary movements of cranks; and sinceaccidental movements of these elements are liable to seriously injurethe operator, great care has been exercised in designing the automaticstopping device. In actual practice, however, the brake and the clutchare not absolutely positive in the per- They are liable to slip,especially after long continued service, and as a consequence,'theoperator is exposed to the danger of unreliable safety devices.

In accordance with the preferred form of my invention, the machine maybe provided with the usual automatic stopping devices, and to compensatefor the uncertain action of such devices, the new structure includes asafety device adapted to stop the cutting elements when the firstmentioned devices fail to perform their functions. Briefly.

other stopping devices fail to stop the cut ting' elements,the safetydevice will then perform its function by serving as an absolutelypositive stop for said cutting elements.

WVith the foregoing and other objects in view the invention comprisesthe novel construction, combination and arrangements of partshereinafter more specifically described and illustrated in theaccompanying draw ings wherein is shown the preferred embodiment of theinvention; however it is to be understood that the invention comprehendschanges, variations and modifications which come within the scope of.the claims hereunto appended.

Figure I is a semi-diagrammatical view of a paper cutting machineequipped with a safety device constructed in accordance with myinvention.

Fig. II is a side elevation of the machine.

Fig. III is a fragmentary vertical section showing the knife carrier,.the' pressure bar and'the stop pins which form part of thesafety device;

Fig. IV is a fragmentary section illustrating the tripping devicewhereby the clutch shifter is actuated to release the clutch.

Fig. V is a fragmentary section illustrating the automatic brake.

The machine I have shown to illustrate the invention comprises sidewalls or frames 1 connected by a horizontal table 2 adapted to supportthe paper or other material below a knife carrier 3 and pressure bar Aknife 3 is secured to the lower margin of the knife carrier. Thepressure bar and knife carrier are adapted. to reciprocate in the sidewalls or frames 1, as is well understood in this art, the pressure barmoving downwardlyto clamp the paper (not shown) during the cuttingoperation. The knife carrier 3 has an inclined guidelug 5 (Fig. I)fitted to an inclined guide 6, so as to guide the, knife in the usualmanner.

The power mechanism (Fig. Dwincludes a power shaft 7 provided with aclutch memher 8 movable toward and away from a driven clutch member 9.The driven mechawith said wheel 11, a shaft 13 to which the .nismcomprises a shaft section'lO fixed to the wheel 12 is fixed, and crankwheels 14 and 15 fixed to the respective ends of shaft 13. A shaft 16(Fig. II) parallel with the shaft 13, is provided at its ends with crankwheels 15 which are connected to the pressure bar 4 by means ofconnecting rods 17. The crank wheel 15', at one end of shaft 16, isprovided with teeth which mesh with teeth on the crank wheel 15. 18designates rods connecting the crank wheels 14 and 15 to the knifecarrier 3.

WVhen the clutch member 8 on the power shaft engages the driven clutchmember 9, power will be transmitted to the crank wheels at the ends ofthe shafts 13 and 16, and the pressure bar and knife carrier willreciprocate in response to the rotary movements of these crank wheels. Ido not deem it necessary to show the means for allowing the shaft 16 tomove independently of the pressure bar 1, such details being immaterialin so far as the present invention is concerned.

The automatic brake (Figs. I and V) comprises a brake drum 19 fixed tothe shaft 13, a contraetible friction band 20 surrounding said drum,said contractible band consisting of two semi-circular sectionspivotally connected together at 20, as shown in Fig. V. 21 designatesbolts passing through lugs which extend from the semi-circular brakeband sections, and also through a lug 22 formed on a stationary part ofthe machine. Light springs 23 (Fig. V), surrounding the respective bolts21 at points below the lug 22, tend to force the brake band sectionsonto the friction drum 19. The springs 23 merely maintain thecontractible brake band 20 in engagement with the friction drum 19; theydo not cause any substantial braking action. The means for contractingthe brake band 20 includes a cam 24 fixed to the shaft 13, a camactuated arm 25 having a roller which engages the cam 24, a rock shaft26 to which said arm 25 is rigidly secured, a relatively short arm orplate 27 fixed to the rock shaft 26, and a pair of abutment screws 27fitted to said arm or plate 27. A pair of gear wheels 28, secured to theabutment screws 27, mesh with each other, as shown most clearly in Fig.I, so as to allow the abutment screws to be adjusted simultaneously.Referring to Fig. V, it will be observed that the cam 24 on the shaft13. is adapted to actuate the elements 25 26, 27 and 27, soas tocontract the brake band 20. This brake has two functions; (1) itprevents the heavy cutting elements from dropping very rapidly, bygravity. during the operation of the machine, and (2) it serves as abrake for stopping the cutting elements when the clutch member 8 isreleased from the clutch member 9.

The means for actuating the clutch CO1:1-

prises an ordinary clutch shifting arm 29 (Fig. I) fitted to' the clutchmember 8, and rigidly secured, at its lower end, to a shaft 30. Astarting handle 31 (Fig. I), fixed to the shaft 30, may be actuated byhand for the purpose of engaging the clutch member 8 with the clutchmember 9, thereby starting the machine. 32 designates a detent armrigidly secured to the shaft 30 (Fig. I) and provided with a pin orroller 32 adapted to enter notches in a retaining bar 33. This retainingbar is pivotally supported at its lower end. 33 designates a springconnected to the upper end of the retaining bar 33, so as to yieldinglyforce said bar into en gagement with the pin or roller 32 which extendsfrom the detent arm 32. When the clutch and clutch shifter occupy thepositions shown by full lines in Fig. I, the pin or roller 32 lies inthe upper notch in the retaining bar 33, thereby yieldingly holding theclutch member 8 in engagement with the clutch member 9. When the clutchis released the clutch member 8 and the clutch shifter occupy thepositions shown by dotted lines in Fig. I, and the pin or roller 32 thenlies in the lower notch in the retaining bar 33.

The means for shifting the clutch automatically, to stop the cuttingelements in their elevated positions, comprises a finger 50 extendingfrom the shaft 30 (Figs. I and IV) and adapted to be engaged by atripping dog 51, the latter being pivotally connected at 52 to a collar53 on the shaft 13. A spring 54 tends to retain the tripping dog 51 inthe position shown by dotted lines in Fig. IV. When the cutting elementsreach their elevated positions, the tripping dog 51 strikes the finger50, thereby elevating said finger, as shown in Fig. IV, with the resultof turning the shaft 30 to which the clutch shifting arm 29 is secured.This releases the clutch, and ordinarily causes the cutting elements tostop in their elevated positions, the automatic brake being appliedimmediately before the clutch is released.

In starting the machine, the starting handle is moved by hand to theposition shown by full lines, thus forcing the clutch member 8 intoengagement with the member 9. The cutting elements then move downwardlyin response to the movements of the driving mechanism, thereafter movingupwardly to the starting position where they are stopped by the actionof the automatic brake and clutch shifter.

The ordinary automatic stopping device, consisting of an automaticfriction brake and an automatic clutch shifter, usually stops thecutting elements in a very satisfactory manner, but such devices are notabsolutely reliable. If no additional safety device is used, theoperator is exposed to the risk of injury from the cutting elements wheneither the brake or clutch shifter fails to perform its function. Toavoid this danger or risk, I have devised a safety device whereby thecutting elements are positively stopped when the brake or clutch shifterfails to accomplish the desired result.

The safety device I have shown to illustrate the invention comprises, apair of horizontal stop pins or bolts 34 slidably mounted in bearings atthe sides of the machine and adapted to enter elongated recesses 35 inthe knife carrier 3. A second pair of pins or bolts 36 are adapted toenter elongated recesses in the pressure bar 4. A rock shaft 37,extending across the machine, is provided with a series of upright armshaving their upper ends connected to the stop pins 34 and 36. The meansfor transmitting movement from the starting handle 31 to the rock shaft37 comprises a short arm extending from said rock shaft (Fig. II), alink 39 connecting said arm to an arm 40, a rock shaft 41 to which thearm 40 is secured, an arm 42 fixed to said rock shaft 41, and a link 43connecting said arm 42 to the starting handle 31. the finger 50 (Fig. I)are both secured to the shaft 30, it will be apparent that all of theconnections just described will be actuated by the tripping dog 51 whenthe latter strikes the finger 50. As a consequence, the pins or bolts 34and 36 are automatically inserted into the cutting elements when thelatter reach their elevated positions. When the starting handle 31 isshifted to the position shown by full lines in Fig. I, for the purposeof starting the machine, movement is transmitted from said handlethrough the link 43, arm 42, shaft 41, etc., to the stop pins 34 and 36,thereby withdrawing said stop pins from the cutting elements. When theautomatic brake and clutch perform their functions properly, the stoppins are ineffective; they merely move into and out of the elongatedslots in the cutting elements without in any way interfering with themovements of the machine. However, when the cutting elements fail tostop in response to the action of the clutch and brake, the stop pinspositively stop the cutting elements and lock them in their elevatedpositions. .In this event, some part of the machine may break, and toavoid the danger and expense of breakage at some uncertain point in themachine I preferably weaken the connections 17 and 18 by the use ofrelatively weak or frangible pins 45, as shown most clearly in Fig. II.

The stop pins or bolts 34 and 36 are preferably beveled at their innerends (Fig. II) which lie adjacent to the cutting elements. If, onaccount of looseness in the connections, or for any other reason, a stoppin Since the starting handle 31 and happens to project slightly intothe path of a cutting element when the latter moves up wardly, the upperedge of the cutting ele ment will strike the beveled end face of theprojecting stop pin and force it out of the way Without injuring anypart of the machine.

I claim 1. A machine having an operating means, a driven member operableby said operating means, an automatic stopping device actuated by saidoperating means to stop said driven member, a manually controlledstarting member associated with the aforesaid parts to provide for thestarting of said operating means, and a normally ineffective stoppingdevice adapted to stop said driven member automatically when saidautomatic stopping device fails to perform its function, said normallyineffective stopping device being movable to its operative position inresponse to movements of said operating means and movable to itsinoperative position in response to movements of said starting member. I

2. A machine having an operating means, a driven member operable by saidoperating means, an automatic stopping device actuated by said operatingmeans to stop said driven member, a manually controlled starting memberassociated with the aforesaid parts to provide for the starting of saidoperating means, and a second stopping device adapted to stop saiddriven member when said automatic stopping device fails to perform itsfunction, both of said stopping devices being movable to their operativepositions in response to movements of said operating means and movableto their inoperative positions in response to movements of said'startingmember.

3. A machine having an operating means, a driven member operable by saidoperating means, an automatic stopping device actuated by said operatingmeans to stop said driven member, said automatic stopping deviceincluding a power transmission clutch and a brake, a manually operatedstarting member whereby said clutch is shifted to start said operatingmeans, and a second stopping device adapted to stop said driven memberwhen said automatic stopping device fails to perform its function, saidsecond stopping device being movable automatically to its operativeposition in response to movements of said operating means.

4. A machine having an operating means, a driven member operable by saidoperating means, and a safety device including an obstruction movableinto the path of and adapted to stop said driven member, said operatingmeans including a power transmission member having a relatively weakportion adapted to break so as to discon tinue the transmission of powerto said driven member when said safety device becomes eti'ective.

5, A machine having an operating means, a driven member operable by saidoperating means, automatic means for stopping said driven member, andsafety device adapted to stop said driven member when said automaticmeans fails to perform its function, said operating means including apower transmission member 11 ving a relatively weal; portion adapted ton-eak so as to discontinue the transmission of Pew-e1 to said drivenmember when said safety device becomes effective.

6. A. machine having operating means, a driven member operable by saidoperatingmeans, and a positive stop device movable into the path of saiddriven member so as to stop the latter automatically, the portion ofsaid positive stop device which lies adjacent to .aid driven memberbeing so formed that the stop device will be actuated by the drivenmember when said stop device is accidentally positioned in the path ofthe driven member.

7. In a machine of the character described driven member movable toiva"d and away for stopping said driven member in an elevated position, anda normally ineffective safety device whereby said driven member isstopped in an elevated position when said automatic means fails toperform its function, said normally ineffective safety device includinga stop member movable into the path of said driven member to positivelystop the latter in an elevated position, and said stop member beingactuated'by said operating means.

8. In a paper cutting machine, vertically movable cutting elements,opera-ting means whereby said vertically movable cutting elements arereciprocated toward and away 't'rom the Work, automatic means for stepping said vertically movable cutting eleonts in elevated positions, andanormally t'fective safety device whereby said verirally movable cuttingelements are stopped elevated positions when said automatic means failsto perform its function, said normally inefi'ec t1 we safety deviceincluding positive stop members movable into the paths oi said cuttingelements, and means or transn'iitting movement from said operating meansto said step members.

in testimony that I clann the foregoing l hereunto afiix my slgnature.

CHARLES F. PFLANZE.

